Siouffi S Y, Kwasnik E M, Khuri S F
Department of Surgery, West Roxbury Veterans Administration Medical Center, Massachusetts 02132.
J Surg Res. 1987 Oct;43(4):360-78. doi: 10.1016/0022-4804(87)90093-x.
An adequate balance between oxygen supply and demand is a basic requirement for normal cardiac function. When oxygen supply does not meet the demand, progressive cellular damage occurs leading to cardiac dysfunction and, ultimately, tissue death. While traditionally "ischemia" has been defined as decreased oxygen supply secondary to a decrease in blood flow, and "hypoxia" as decreased oxygen supply secondary to a decrease in oxygen tension, this review defines ischemia in its broader sense, namely as a pathophysiologic state in which there is a lack of oxygen relative to the demand for it. In a large number of experimental studies involving the heart, there is need to promptly recognize the ischemic state, to monitor its course in vivo, and to quantify it. Because of cardiac autoregulatory mechanisms, research methods which attempt to quantify supply (e.g., measurement of myocardial blood flow) and/or demand (e.g., measurement of myocardial oxygen consumption) do not necessarily reflect the status of the balance between supply and demand. An imbalance between myocardial supply and demand is more likely to be reflected by metabolic fluxes and by the accumulation of products specific to the ischemic state. Thus, the purpose of this review is to summarize the various methods available to the cardiac surgical investigator today for the metabolic quantification of myocardial ischemia. Due to the complexity of the heart and its inherent regional differences, myocardial ischemic changes are frequently regional in nature. Thus, this review will address metabolic methods for the regional quantification of myocardial ischemia.
氧供与需求之间的适当平衡是心脏正常功能的基本要求。当氧供不能满足需求时，会发生渐进性细胞损伤，导致心脏功能障碍，最终导致组织死亡。传统上，“缺血”被定义为继发于血流减少的氧供减少，“缺氧”被定义为继发于氧张力降低的氧供减少，但本综述将缺血定义为更广泛的意义，即相对于需求而言存在氧缺乏的病理生理状态。在大量涉及心脏的实验研究中，需要及时识别缺血状态，在体内监测其进程并进行量化。由于心脏的自身调节机制，试图量化供应（例如测量心肌血流量）和/或需求（例如测量心肌氧消耗）的研究方法不一定能反映供需平衡的状态。心肌供需失衡更可能通过代谢通量和缺血状态特有的产物积累来反映。因此，本综述的目的是总结当今心脏外科研究人员可用于心肌缺血代谢量化的各种方法。由于心脏的复杂性及其固有的区域差异，心肌缺血变化通常具有区域性。因此，本综述将探讨用于心肌缺血区域量化的代谢方法。
